The present invention relates to office furniture and more particularly to chairs including a vertically adjustable back assembly.
Different forms of chairs are available which are principally adapted to the office environment or which are task oriented. Such chairs generally include adjustable components to adapt them to the particular user and task. For example, the chairs may include vertical height adjustments for the seat, a swivel and tilt chair control and vertically adjustable backs. An example of a chair including vertically adjustable back assemblies may be found in commonly owned U.S. Pat. No. 4,043,592 entitled Adjustable Seat Back Mechanism and issued on Aug. 23, 1977. The chair disclosed in such patent includes a single vertical seat back support to which a seat back is slidably mounted. A seat back mechanism includes a channel shaped support plate secured to the back of the chair, a housing and a latching arrangement carried by the housing to permit stepwise vertical adjustment of the housing and support plate relative to the vertical support post of the chair. Examples of other chairs including back height adjustment mechanisms may be found in U.S. Pat. No. 3,526,430 entitled Back Height Adjustment Mechanism and issued on Sept. 1, 1970 to Eldon and U.S. Pat. No. 4,616,877 entitled Chair With Back Height Adjustment and issued on Oct. 14, 1986 to Slaats et al.
Many of the prior back adjustment assemblies have suffered from undue complexity, difficulty in assembly, unsightly appearance and difficulties in operation. Generally, the prior back height adjustment mechanisms require that the user operate them with both hands.
A need exist for a relatively simple, easily manufactured adjustment mechanism which is aesthetically pleasing and which provides increased ease of assembly, reliability and ease of use.